Design of Axial Modular-Flux Reversal Permanent Magnet Machines With Different Magnetization Modes

This article investigates the optimal air-gap flux density harmonics interaction mechanism of the axial modular-flux reversal permanent magnet (AM-FRPM) machines with different magnetization modes. Based on the PM and armature reaction field analysis, the similarities of harmonic interaction mechanism between two AM-FRPM machines are revealed, and then, the stator-slot and rotor-pole combinations with higher output torque can be determined. In addition, the optimal modular part angles are deduced to suppress cogging torque based on effective harmonic cooperation. Furthermore, a comparison between the three chosen AM-FRPM machines and the conventional FRPM machine is conducted, and the characteristics are verified by finite-element analysis and experiments.